1. Field of the Invention
The present invention relates to protective covers for swimming pools.
2. Description of the Prior Art
Swimming pool covers have been employed for quite some time as a measure of reducing the extent to which leaves, twigs, and blowing debris collect in a swimming pool. By protecting the pool from airborne contaminants in this fashion when the pool is not in use, the necessary frequency of cleaning the pool is reduced. Pool covers are also employed as safety devices to prevent small children from inadvertently falling into a pool and drowning. Pool covers also serve as a means of conserving energy. The placement of a cover over a swimming pool reduces thermal loss from a pool both at night and on cool days, whether the pool employs an active heating plant, or whether it is only passively heated by the sun.
Conventionally swimming pool covers have been inordinately sophisticated, complex and expensive. Conventional pool covers are wound on powered rollers which are driven by an electric motor through a cable system to retract the pool cover onto a drum, or to withdraw the pool cover and extend it laterally outward to cover the surface of the pool. In conventional systems, the edges of the pool cover are provided with enlarged beads or other guides which ride in tracks that extend along the sides of a pool. The track system can either be installed on the deck of the pool, below grade along the upper edge of the side of the pool, or on the underside of a ledge that overhangs the pool. When such track systems are installed on the pool deck, they present unslightly upward projections. Leaves and other debris tend to collect in the structure of the tracks, and the tracks themselves present hazzards to users of the pool who are quite likely to stub their toes or otherwise injure their bare feet on the tracks. When the tracks are installed along the vertical sides of the pool at the upper edges thereof, they present hazzards to swimmers entering and obstructions to users leaving the pool. When the tracks are installed on the undersides of overhanging ledges, they are extremely expensive to install, very difficult to service, and such installations can only be performed for existing or newly constructed ledges, which are themselves quite expensive and space consuming. Furthermore, the track systems for conventional pool covers can only be employed on pools which are shaped with parallel sides unless the tracks are placed above grade on the deck.
Other swimming pool covers do not employ tracks, but rather utilize floats or covers constructed in rigid sections which float upon the surface of the water. While the disadvantages of the track systems are avoided, floating pool covers have their own drawbacks. Specifically, leaves, twigs, branches, papers and other debris fall onto the surface of the cover and are frequently dumped into the pool over the edges of the cover when the cover is withdrawn. Consequently, such covers are largely ineffective in preventing contamination of the pool. Furthermore, floating covers do not provide good protection for the safety of small children, and indeed, may well be more dangerous than no cover at all, since youngsters can fall into the pool at the edges of the covers and become entrapped beneath the floating cover.